In case you still haven't been successful, try this, flash twrp 3.3.1-0 which should work to wipe partitions and rightly install the rom. https://dl.twrp.me/star2lte/twrp-3.3.1-0-star2lte.img.tar.htmlThanks for all the help so far but still no success.
Before installing xfire, formatting data, wiping system, cache and dalvik cahce.
If I do not format data I get an error on mounting data.
At installation xFire (I did not take the file you mentioned because that's for the S9, took the one for the S9+ instead).
Applying CSC feature MOD and then the next line
Failed XML File is encrypted
At the end of the installation I get following line in red
Failed to mount /odm no such file or directory
After restarting xFire the installation process looks exactly as the one for the Stock ROM, after booting it also looks exact as stock ROM.
Installing lineage (with format data, wipe system, cache , dalvik cache).
Lineage starts up, moving logo and then reboots into twrp (recoveryà just as happended before.
Any other ideas?
Flash custom rom OneUi 2.5
You can flash the last twrp 3.6.0 and then install a custom OneUi 2.5 ROM, but after you flashed the rom before rebooting, install Magisk v23.0 too https://cdn.magisk.us/Magisk/Magisk-23.0.zip